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%I #4 Sep 25 2017 07:14:13
%S 1,1,1,1,5,5,1,2,6,3,11,11,13,91,35,20,68,51,57,19,1,11,253,46,50,325,
%T 117,63,203,29,31,248,88,187,85,15,111,703,247,26,82,287,301,473,165,
%U 345,1081,188,28,35,85,221,689,477,495,770,266,551,1711,59,61,1891,93,48,1040,715
%N a(n) = denominator of constant lambda(n) involved in a recurrence for the Atkin polynomials A_k(j).
%H M. Kaneko and D. Zagier, <a href="http://www2.math.kyushu-u.ac.jp/~mkaneko/papers/atkin.pdf">Supersingular j-invariants, hypergeometric series and Atkin's orthogonal polynomials</a>, pp. 97-126 of D. A. Buell and J. T. Teitelbaum, eds., Computational Perspectives on Number Theory, Amer. Math. Soc., 1998
%F For formula see Maple code.
%e 720, 546, 374, 475, 2001/5, 2294/5, 410, 903/2, 2491/6, 1342/3, 4602/11, 4891/11, ...
%p lambda:=proc(n) if n=1 then 720 else 12*(6+(-1)^n/(n-1))*(6+(-1)^n/n); fi; end;
%Y Cf. A145226.
%K nonn,frac
%O 1,5
%A _N. J. A. Sloane_, Feb 28 2009